Χρόνου δὲ διελθόντος νόσῳ ὑδερικῇ περιπίπτει, καὶ ὁρῶν τὸ πάθος δυσίατον – ἐπὶ τοσοῦτο γὰρ ἐπετείνετο ὡς καὶ ἡνίκα ἀπουρεῖν ἤμελλε σανίδα κατὰ τοῦ ἤτρου ἐπετίθει· ἐστρέφετο γὰρ αὐτοῦ τὸ αἰδοῖον καὶ κατὰ τοῦ προσώπου αὐτοῦ τὰ οὖρα ἔπεμπεν. ἔλεγχος δὲ ἦν τοῦτο τῆς παρανομίας τῆς ἑαυτοῦ, ὑπὲρ ἧς ταύτην δίκην ὑστάτην ἐξέτισε τοῦ εἰς τὴν ἀνεψίαν τὴν οἰκείαν γάμου. διαθήκας οὖν ἐξετίθει, ὥστε Κωνσταντῖνον καὶ Ἡράκλειον τοὺς υἱοὺς αὐτοῦ βασιλεῖς ἰσοτίμους εἶναι, καὶ Μαρτῖναν τὴν αὐτοῦ γυναῖκα τιμᾶστθαι παρ’ αὐτῶν ὡς μητέρα καὶ βασίλισσαν. ἐκ τούτου λοιπὸν ἐτελεύτα ζήσας ἔτη ἓξ καὶ ἑξήκοντα, ἐν δὲ τῇ βασιλείᾳ διανύσας ἔτη τριάκοντα μῆνας τέσσαρας ἡμέρας ἕξ.
(St Nicephorus, Breviarium 27)

Sometime later he* fell ill with the dropsy and realized that his disease was difficult to cure, for it grew to such an extent that when he was about to urinate, he would place a board against his abdomen: <otherwise> his private parts turned round and discharged the urine in his face. This was in reproof of his transgression (namely, his marriage to his own niece) on account of which he suffered this ultimate punishment. He set forth a testament whereby his sons Constantine and Herakleios were to be emperors of equal rank and his wife Martina was to be honored by them as mother and empress. So he died of this <disease> at the age of sixty-six after a reign of thirty years, four months and six days. (tr. Cyril A. Mango)

* Byzantine emperor Heraclius.